ya know...
I actually kinda like orecks, they are very light and easy to use, and i think they often perform better than what people give them credit for. Especially the "newer" style such as the 21, gold, etc. While they cannot compare to a direct air or tandem air machine with larger fans, i do feel they can at times match or out perform bypass machines.
To compare the performance of the vacuums i have i bought hot pink sand, distributed an amount on a rug, worked the sand in, and then counted the number of strokes it took to remove all visible sand. *note 1 stroke = 1 pass forward + backward* The Xl-21 took 3, the XL ultra i no longer have had mixed results so i averaged it's score and gave it a 4, the xl-21 scored better than the Miele S7, Miele Silver moon, and Rainbow E-2 (black) all of which scored a 4. the 21 matched the score of the lindhaus Healthcare Pro, Filter Magic w/Vibragroomer III, Patriot w/ lindhaus PB-14, and Royal power team.